rm question - UNIX for Dummies Questions & Answers

SeanWuzHere · #1 12-02-2006

I want to use the rm command to delete files in a directory. But I want to be able to set a variable that says how many arguments it will delete. So for instance, if I set a variable to null,.. (i.e. MAXFILES="") then it will just delete all the arguments. But if I set MAXFILES=2 for instance, then it will delete only 2 arguments. I'm writing a program to do this, and there are other specifications too,.. but I think I have most of it figured out but I can't seem to get past this one hurdle. Any thoughts? Great thanks in advance to any advice on this.

Btw,... before I start writing the program, I want to be able to practice setting the variable and then using that variable just using the command at the command prompt. In other words, I want to be able to just do something like...

$ MAXFILES=""
$ rm arg1 arg2 arg3
$

or

$ MAXFILES=2
$ rm somethinggoeshere (and it deletes the files per the number of arguments defined in the variable above.)

This way it will hopefully sink in through my thick cranium on how this is working.

System Shock · #2 12-02-2006

Let me get this straight.
You want to set a variable that will limit the number of files you can delete in the command line, ex:
if you set MAXFILES to 3, and you type something like

Code:

 delete file1 file2 file3 file4 file5

only file1 file2, and file3 will be deleted.

Is that what you are looking for?

SeanWuzHere · #3 12-02-2006

Quote:

Originally Posted by System Shock

Let me get this straight.
You want to set a variable that will limit the number of files you can delete in the command line, ex:
if you set MAXFILES to 3, and you type something like

Code:

 delete file1 file2 file3 file4 file5

only file1 file2, and file3 will be deleted.

Is that what you are looking for?

Yeah. Something like that. Here is the code I have so far for the program. It kinda sorta works but either I'm doing something wrong or it's missing something or I dunno.

Code:

#!/bin/bash
# Program: myrm

if [ "$#" -le 0 ]
then
        echo "Not enough arguments"
        echo "Usage: myrm [arg1] [arg2] etc..."
        exit 1
fi

MAXFILES=""
FILECOUNT=$(ls | wc -l)

if [ -n "$MAXFILES" ]
then

        if [ "$FILECOUNT" = "$MAXFILES" ]
        then
                for i
                do
                        rm -rf $1
                        shift
                done

        elif [ "$MAXFILES" > "$FILECOUNT" ]
        then
                echo "Would you like to delete these files?"
                read choice

                case "$choice"
                in
                        y)      for i; do rm -rf $1; shift; done;;
                        n)      echo "Thank you, have a nice day";;
                        *)      echo "Invalid choice"
                                exit 2;;
                esac
        fi

elif [ -z "$MAXFILES" ]
then
        for i in $1 $2 $3 $4 $5 $6 $7 $8 $9 ${10}
        do
                rm -rf $1
                shift
        done
        exit 0


fi

reborg · #4 12-02-2006

two comments.

1. Give the full path to the rm command, it may be aliased.
2. Test for wildcards, if you pass in a quoted wildcard, it may not behave as expected.

kapilraj · #5 12-02-2006

why do you want to do this ?

rm file1 file2 will delete file1 and file2 , rm * will delete everything. I can not undestand your requirement or this is a stupid requirement.

Regds,

Kaps

SeanWuzHere · #6 12-02-2006

Quote:

Originally Posted by kapilraj

why do you want to do this ?

rm file1 file2 will delete file1 and file2 , rm * will delete everything. I can not undestand your requirement or this is a stupid requirement.

Regds,

Kaps

Yeah,.. I guess when we are first learning something people give us stupid questions to figure out. LOL. Believe me,.. I have way better things I'd rather spend my Saturday night doing but I have to get this finished. Also,.. just remember,.. this is probably really easy for you because you are probably an expert with this but I am just a n00b so there's a lot that doesn't make sense to me yet. But I'm getting better and better at it everday.

Well, anyway,.. I think I have it all figured out for the most part. Now I just have to make it so that if the number of arguments exceed the number specified in MAXFILES, then it will ask me to confirm the deletion. That shouldn't be too hard. Anyway,.. thanks all for the great help.

Here's my revised version which works the way I need it to for the most part.

Code:

#!/bin/bash
# Program: myrm

if [ -z "$MAXFILES" -a "$#" -ge 1 ]
then
        for MAXFILES in $1 $2 $3 $4 $5 $6 $7 $8 $9 ${10}
        do
                echo "deleted$MAXFILES"
                shift
        done
        exit 1
fi

if [ -n "$MAXFILES" -a "$#" -ge 1 ]
then
        MAXFILES="$*"
        rm -rf $MAXFILES
fi

Then I just do something like this:

Code:

$ MAXFILES=56 ./myrm f1 f2 f3 f4
# then it deletes the 4 files because they are less than the amount specified in MAXFILES.
or
$ MAXFILES= ./myrm f1 f2 f3 f4

blah blah blah

Also,.. I have just an echo command in the top section just to make things easier. I'll go back and put the correct commands in there later. I just mainly needed to figure out HOW to do it and I think I got it now.

SeanWuzHere · #7 12-03-2006

Whoo hoo! Finally after working on this all day I finished it. I feel so accomplished now.

Code:

#!/bin/bash
# Program: myrm

if [ "$#" -le 0 ]
then
        echo "Not enough arguments"
        echo "Usage: myrm [arg1] [myarg2] etc.."
fi

if [ -z "$MAXFILES" ]
then
        for i in $1 $2 $3 $4 $5 $6 $7 $8 $9 ${10}
        do
                rm -rf $i
                shift
        done
        exit 1
fi

x=$(ls | wc -l)

if [ -n "$MAXFILES" -a "$#" -lt "$MAXFILES" ]
then
        rm -rf $*
else
        echo "Remove $# files? (y/n)"
        read choice

        case "$choice"
        in
                y)      rm -rf $*;;
                n)      echo "Ok, I will not delete any files then";;
                *)      echo "Invalid option"
                        exit;;
        esac
fi

And here is how it works:

Code:

$ ls
f1  f10  f11  f12  f13  f14  f15  f2  f3  f4  f5  f6  f7  f8  f9  myrm
$ MAXFILES= ./myrm f*
$ ls
f5  f6  f7  f8  f9  myrm
# MAXFILES is set to null and deletes up to 10 files even though I specified more.

$ MAXFILES=2 ./myrm f1 f2 f3 f4 f5
Remove 5 files? (y/n)
y
$ ls
f10  f11  f12  f13  f14  f15  f6  f7  f8  f9  myrm
# MAXFILES is set to 2 but I specified 5 files to delete. So it asks me y/n to confirm.

$ MAXFILES=5 ./myrm f1 f2 f3
$ ls
f10  f11  f12  f13  f14  f15  f4  f5  f6  f7  f8  f9  myrm
$ 
# MAXFILES is set to 5 and since I have specifed less than 5 arguments, it just does it without question.

Anyway,... case closed.

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